Method of removing husks from oats



Dec. 9, 1952 s. JACQBSON 4 METHOD OF REMOVING HUSKS FROM OATS Filed June4, 1951 2 SHEETS-Sl-IEET 1 Dec. 9, 1952 s. JACOBSON 2,620,841

METHOD OF REMOVING HUSKS FROM OATS Filed June 4, 1951 2 SHEETS-SHEET 2Jar/61% c/a wZov/V iz'zj 142% J Warm Patented Dec. 9, 1952 UNITED STATESPTENT OFFICE METHODOF REMOVING HUSKS FROM OATS Sven Jacobson,Gothenburg, Sweden Application'June' 4, 1951, Serial No; 229,765- InSwedenOctober 19; 1944 4: Claims. 1.

This application is. a. continuation-in-part: of UnitedStatesapplication Serial No. 622,601, filed October 16, 1945', and.subsequentlyabandoned.

Cereals, for instance cats, have. usually been hulled after beingsubjected to. a suitable preliminary operation by being passed throughahusk removing machine in which. the husks are removed mechanically, forexample between apair. of stones. The usual methods however allhave thedisadvantage that: the grain" toazgreat extent becomes worn and brokenresulting. in considerable loss in the finished product.

The present invention has for its purpose to provide a method in whichthe'abovementioned disadvantages are avoided andwhich will be simplerthan .thehithertousedmethods, since it can be used withoutgradingintosizes and which need not be preceded by a drying process to dry thegrain.

According to my invention, theoats are subjected during a suflicientlength of time toaerodynamicaction to force open the husks or/and breakthem off and thereby layabare the kernels.

Two embodiments of apparatus for carrying out the invention areillustrated in the accompanying drawing in which Fig. 1' is an apparatusfor treating comparatively smallbatch'es of oats and Fig. 2 shows anapparatus for the continuous treatment of greater quantities. Fig, 3shows an apparatus, which combines the advantages of the apparatusesaccording to Figs. 1 and 2.

In Fig. l the numeral I designates'a cylinder of perforated plate'or ascreen, which is 1 connected to an unperforated conical part 2. A pipe 3is connected to the bottom of the conical part 2 and at its other end isconnected to a source of pressure for instance a compressor or a blowernot illustrated in the drawing. Theupper end of the cylinder is closedby a piston 4, which is;preferably adjustable for reasons whichwill beapparent fromthe following.

The'huskingor hulling process is carried out in the following manner; Asuitable quantity of cats is introduced" into theapparatus and the airpressure is turned on. Thecompressed air flows up into the cylinder,where itexpands and then escapes from the cylinder byway. of the.perforations. The cats are thrown up into the cylinder and caused tocirculate rapidly by the stream of air and are repeatedly exposed to theaction of the air. During the operation, the husks are forced open andremoved from the kernels. The powerful stream of air forces its wayunder the husks, which are opened up more or less like an open umbrella.The husks are then broken on,

either through the direct-aerodynamic action of the air or through theimpact of the oats against eachother, or against thewalls ofthecylinder; At the higher pressures the husks will be removed withoutthe piston 4 and the piston should in these cases be removed; In thiscase means must be provided for gradually retarding the velocity of the.oats, for instance a sufiiciently long free trajectory or a cyclone. Atthe-lower pressures, however; the effect will be increasedxif the pistonis adjusted in a suitable manner sothattheoats are thrown against it. Itshould benotedzhowever, that the effect is decreased'iffithe piston ispositioned too close tothe mouth: ofthepipe'3. The piston can in each.individual case be ad. justed so that the maximum client is obtained.

The method can be carried out by continuing the operation until acertain quantity, for instance, 20 or 25% or more, ofthe oats hasbeenhulled. The operation is then discontinued and the husks and the hulledcats are" removed, after which the operation is resumedand continued inone or more further steps until the remaining oats have been hulledascompletely as possible. Alternatively, the operation oan'be carriedout in a single steppreferably with higher pressure and during a greaterlength of time until -or or more of the oats have been hulled.

It has been found that the pressure at the mouth of the pipe 3 should beof the magnitude of at least 2 leg/cm: higher than" pressure outside ofthe cylinder, and a difference in pressure of between '7 kg./cm. and 10kg.'/cm. has been found suitable. The velocity of the air is'preferablyof the magnitude 300 III/sec. or more; The time required'for completionof'the operation is considerably increased if the pressure is loweredand; can be somewhat shortened'by raising the pressure; The greaterthepressure, hoWeWLthB greater will; be the loss due to breakage of thekernels and the aforesaid pressure difference should not materiallyexceed 12 kg/cmF" The time is also influenced'by the quantity, of. airper unit of time and by the quantity of oats inthe batch. It has insomecasesbeen foundof. ad.- vantage to increase the new of air by,increasing the diameter of the. pipe3I and atthe Same time lowering thepressure in order todiminish. the breakage.

The apparatus illustrated in Fig. 1 is especially useful for making aquick and reliable examination of a sample of oats for determining thequality of a delivery of cats.

An apparatus for continuous operation is shown in Fig. 2, in which thecylinder 5, the conical part 6, the pipe I and the piston 8 have thesame functions as in the apparatus shown in Fig. 1. At the bottom of theconical part 6 there is, however, an entrance pipe 9 for the oats,surrounding the air pipe I and extending somewhat above the mouth of thelatter. The pipe is enlarged somewhat at its lower end, which is locatedin a container I for oats. A supply pipe I I leads from a largercontainer to the container I0 and serves to supply oat to the containercontinuously as oats are removed to the cylinder. A pipe I2 from thebottom of the conical part 6 serves to remove the hulled oats from thecylinder.

Fig. 3 shows an apparatus which may be said to combine the advantages ofthe batch method as used in the apparatus shown in Fig. l and thecontinuous method as used in the apparatus shown in Fig. 2. Beforeadmitting the oats to the apparatus shown in Fig. 3 it is, however,necessary to grade them to size, the diameter of the grains of oats ineach batch varying only within an interval of one to two tenths of amillimeter. Each grade of oats is treated separately in the apparatus.

The numerals I3 and I4 designate separate cylinders of perforated plate.The conical part I5, the pipe I6 and the piston I'I correspond to, andhave the same functions as, the correspondingly numbered parts inFig. 1. The cylinder It has a greater diameter than the cylinder I3 andan annular opening I8 is formed between the two cylinders. Whole grainsof oats, husks and kernels escape through the opening I8 and arecollected in a circular trough I9 under the opening I8 from which theyare blown by the escaping air out into a chamber 20 surrounding thecylinders I3 and I4. The walls of this chamber are made as sieves, thesize of the perforations being determined by the size of the oats beingtreated. The bottom wall of the chamber 20 is conical and slants towardan annular opening 2| leading back to the entrance to the cylinder I3.The husks and the hulled oats pass through the perforations of thesieve, but oats that have not been hulled pass back to the cylinder I3and are again subjected to the action of the air. A fresh quantity ofgraded oats is supplied to the chamber 20 through a pipe 22 and by wayof the cone I passes into the cylinder I3 for treatment together withthe tailings. The quantity of oats entering through the pipe 22 can beregulated by suitable mechanical (weighing), electrical or optical meansto correspond to the amount of hulled oats escaping from the chamber 20.In this manner, it is possible to adjust the apparatus to work evenlyunder the most economical conditions. In this apparatus, the most easilyhulled oats are immediately removed and the breakage is reduced to aminimum, while more resistant oats receive the required treatment toremove their husks. The stationary sieve forming the bottom wall ofchamber 20 may, if desired, be replaced by a suitable movable sieve toincrease the effect thereof.

As previously set forth, the piston 4 or its equivalent, while in somecases desirable, is not essential to the operation of the apparatus. Ifpresent it should be adjusted to a position, readily determinable bytrial, affording optimum de- '4 hulling with minimum kernel breakage.Obviously, the position of the piston for optimum results will vary withthe pressure of the air and the velocity of the oats.

The method can be used for hulling either dry or undried oats. Insteadof air under pressure, a powerful flow of any other suitable gas, forinstance steam, may be used. The chamber in which the hulling takesplace need not be cylindrical, but may have any other suitable shape. Itneed not necessarily be made of perforated plate, but may instead haveone or more suitably located escape openings for the air.

I claim:

1. The method of hulling oats comprising the steps of introducing theoats to be hulled into a chamber having an admission opening for astream of compressed air and an escape opening for said air, andsubjecting the oats to the repeated action of a continuous stream ofcompressed air entering through said admission opening and into contactwith the oats to be hulled at a pressure of from about 2 kg./cm. toabout 12 kg./cm. above that of the surrounding atmosphere, whereby thehusks are forced or broken open and removed from the kernels solely bythe direct aerodynamic action of said air on the oats.

2. The method of hulling oats comprising the steps of subjecting a massof cats to be hulled within a confining chamber to the repeated actionof a continuous, upwardly directed stream of compressed air projectedinto contact with said mass at a pressure of from about 2 kg./cm. toabout 12 kg./cm. above that of the surrounding atmosphere and whichpasses with substantial freedom through said chamber, whereby the husksare forced open and removed from the kernels solely by the directaerodynamic action of said air on the oats.

3. The method according to claim 1 wherein the air enters the admissionopening at a pressure of from 7 kg./cm. to 10 kg./cm. above that of thesurrounding atmosphere.

4. The method according to claim 2 wherein the air enters the admissionopening at a pressure of from 7 kg./cm. to 10 kg./cm. above that of thesurrounding atmosphere.

SVEN JACOBSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 124,848 Paige Mar. 19, 1872226,471 Arbuckle Apr. 13, 1880 258,912 Goessling June 6, 1882 269,741Taggart Dec. 26, 1882 1,699,441 Negro 1- Jan. 15, 1929 1,874,150 AngerAug. 30, 1932 1,950,069 Stein Mar. 6, 1934 FOREIGN PATENTS NumberCountry Date 20,917 Great Britain Oct. 16, 1905 433,034 Great BritainAug. 7, 1935

